Researcher Samukelisiwe Msweli has identified plant species that are highly inflammable and those of which the flammability is low. Photo: Supplied
A study in the Garden Route has identified highly flammable plant species that significantly increase wildfire risks — an urgent concern as climate change fuels more frequent and intense fires.
Nelson Mandela University researcher Samukelisiwe Msweli has pinpointed certain plants that ignite quickly and burn intensely, making fires more destructive.
Her findings provide crucial insights that can help homeowners, urban planners and environmental managers make informed decisions about which species to plant to aid fire prevention.
“This is tangible information people can use immediately,” Msweli said. “Many will recognise these shrubs and trees from their own gardens.”
Understanding the fire risks of different plant species can help people take preventative measures, and ward off events such as the devastating Garden Route fires of November 2018, in which several people died and homes destroyed.
The study assessed the flammability of 30 woody species, many never studied before. It showed that invasive species such as pine (Pinus pinaster and Pinus radiata), gum and wattle pose particularly high fire risks because of their rapid ignition and intense burning.
“Wattle not only carries fire but also drains water from the soil, and it is not indigenous to this area,” Msweli said. “The high fire risk posed by these species needs to be considered in planting decisions and invasive plant-clearing efforts.”
The alien invasive plants with high flammability are: Coastal/redeyed wattle (Acacia cyclops), black wattle (Acacia mearnsii), black wood (Acacia melanoxylon), inkberry (Cestrum laevigatum) and river redgum (Eucalyptus camaldulensis),
In contrast, native thicket species in the region were found to be less flammable, offering a safer alternative for fire-conscious gardeners and planners.
White milkwood (Sideroxylon inerme), thorn pear (Scolopia zeyheri), candle wood (Pterocelastrus tricuspidatus) and bitou (Osteospermum moniliferum) are indigenous plants with low flammability.
Other native species such as Buchu (Agathosma ovata), dancing thorn (Aspalathus spinosa), monkey plum (Diospyros dichrophylla), spike-thorn (Gymnosporia buxifolia), conebush (Leucadendron eucalyptifolium) and Cape sumach (Osyris compressa) have medium flammability.
But some indigenous species in the area are also highly flammable, including blombos (Metalasia muricata), dune gonna (Passerina rigida), Phylica axillaris, Erica canaliculata and Erica discolor.
Msweli suggests simple steps such as choosing the right plants, keeping gutters clean of dry branches, sweeping up dry leaves and maintaining a clear space around homes to help protect property and lives.
Msweli conducted her research at Nelson Mandela University’s George Campus, known as the green campus for its Natural Resource Science and Management Cluster and its environmental research.
She will now expand on this as part of her PhD at the University of Cape Town, where she will use satellite imaging to assess fire risks across landscapes.
“We will look at the vegetation and then remotely assess whether an area is at risk.
“If you know that these species burn like this, you can detect the risk of a whole area using satellite data. This would result in a landscape being deemed as low, medium or high flammability because of the plant species there.”
This work aims to integrate plant flammability insights into wildfire management strategies to be better prepared for fire threats.
“Fire isn’t always the enemy – it is part of nature,” she said. “Fire has its uses but we need to learn how to live with it safely.”
By applying these findings, she hopes that fire hazards can be reduced, so protecting both human life and biodiversity in the Garden Route and beyond.
Gillian McAinsh is a freelance writer and editor.
